The present invention relates to a magnetic disk device and a magnetic head slider and, more particularly, to a magnetic head slider having a thin-film head portion formed on a slider substrate portion using a thin-film process and a magnetic disk device using the slider.
In the magnetic disk device, a magnetic head slider mounted with a recording/reproduction element flies from a magnetic disk due to a wedge film effect of air, so that recording/reproduction of magnetic data on the magnetic disk is performed. To realize high recording density of the magnetic disk device and resultant increase in capacity of the device or size reduction, it is effective that distance between the magnetic head slider and the magnetic disk (flying height of the slider) is reduced to increase line recording density. Recently, the flying height of the slider is reduced to about 10 nm or at most 10 nm.
A typical magnetic head slider for use in a conventional magnetic disk device includes one which is configured to have a slider substrate portion formed using a sintered-body of alumina mixed with titanium carbide (sometimes expressed as AlTiC) and a thin-film head portion that is formed on the slider substrate portion using a thin-film process and forms an air-bearing surface along with the slider substrate portion. The thin-film head portion is configured to have an alumina insulation film having a coefficient of linear expansion approximately equal to that of the slider substrate portion.
Such a conventional, typical magnetic-head-slider is produced by stacking a metal film, ceramic insulation film, resin film and the like on a wafer forming the AlTiC slider substrate using the thin-film process, and forming a plural number of read/write elements, and finally cutting out individual magnetic-head-slider from the wafer by machining. However, according to such a production method, since the magnetic head slider is cut out by machining, productivity has been low.
Therefore, as described in non-patent literature 1 (IEEE Transactions on Magnetics, vol. 40, 1, 332-336, “Flying-height adjustment technologies of magnetic head sliders”), a magnetic head slider which does not use AlTiC as a material of the slider substrate portion but uses silicon is devised. The use of silicon as the material of the slider substrate portion is for cost reduction by cutting the slider substrate by etching instead of machining to form a slider profile.